This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 13 |
| 3 | 41 |
| 4 | 126 |
| 5 | 379 |
| 6 | 1121 |
| 7 | 3272 |
| 8 | 9449 |
| 9 | 27049 |
| 10 | 76866 |
| 11 | 217079 |
| 12 | 609793 |
| 13 | 1705036 |
| 14 | 4748101 |
| 15 | 13174889 |
| 16 | 36440646 |
| 17 | 100503667 |
| 18 | 276476129 |
| 19 | 758785424 |
| 20 | 2078056481 |
| 21 | 5680052329 |
| 22 | 15497929098 |
| 23 | 42216552431 |
| 24 | 114824352001 |
| 25 | 311871557524 |